Is UNIX Cheaper Than Linux?

Reports of the death of UNIX, as Mark Twain might have said, are greatly exaggerated.

A recent HP-commissioned Forrester Consulting survey finds this to indeed be the case for some enterprises holding fast to their OS of choice despite Linux's
steady move upstream. Are they the last holdouts or an indicator that UNIX still
has much to offer?

That's the message HP is going to great lengths to put across right now, backed up by some research it commissioned Forrester Consulting to carry out.

The research aimed to answer the basic question "Why do users of current RISC/UNIX platforms continue to use UNIX in the face of increasingly robust Linux offerings, often from the same vendors that provide RISC/UNIX platforms, running on less-expensive x86 platforms?"

It's an interesting question because while some companies have moved from UNIX to Linux, enjoying lower costs, increased performance and high reliability, others have steadfastly resisted doing so. The latest IDC statistics show that UNIX sales were flat in the last quarter of 2010, while Linux jumped by almost 30 percent. Windows server sales were up 17 percent in the same period.

To try to shed some light on why, Forrester interviewed IT staff at 15 UNIX-using companies. The key reasons they came up with for sticking with UNIX are:

Availability

Scalability

Ease of maintenance

Security

Partitioning

Total cost of ownership

Of all these, availability was the most important advantage UNIX brings to the party, in the opinion of the IT people interviewed. In particular, the maturity of UNIX clustering and the ease with which it can be set up were mentioned.

Now Linux fans would no doubt argue that their open source servers enjoy high availability and scalability, too. Ease of maintenance is arguably similar, while Linux systems are not exactly plagued by security problems in the way systems running Microsoft's Windows server operating systems are. It's only for really large, high end, mission-critical systems that UNIX probably has the edge over Linux.

Where Linux has been making inroads into traditional UNIX territory is in the less-demanding roles, and as the open source server operating system has matured, it has been steadily moving upmarket to put the squeeze on UNIX. Why? Because Linux is less expensive and runs on standard hardware.

So what's rather striking is that all the interviewees believe that "their UNIX systems were cheaper to manage than the x86 systems running other operating systems such as Linux that would be required to handle the same workloads."

UNIX cheaper than Linux? That's unexpected, but at the very top end it could be true.

The interviewees certainly believe so, for a number of reasons.

UNIX requires less frequent patching and therefore also reduced testing of patches before they go live

UNIX clustering is easier to set up and more reliable than alternatives

If they were to switch to Linux, they would end up with two to four times more systems than they have currently -- with commensurate increases in management costs -- and increases in potential points of failure in non-UNIX environments.

Be careful about taking this data as gospel, however. Remember, the research involved interviewing 15 UNIX users: People pre-selected for their decision to stick with UNIX rather than move to a Linux server OS. We shouldn't expect these guys to say they think Linux offers a lower TCO than UNIX; if they did, they probably wouldn't be UNIX users.

That's not to say those concerned are wrong: For their particular applications UNIX may well offer a lower TCO. What the research really shows is there are some organizations which -- perhaps quite rightly -- believe UNIX still offers a preferable solution, with a lower TCO, than Linux. And that tallies with observations that some organizations are sticking with UNIX -- for the time being at least.

As to the future, it's inevitable that Linux server operating systems will continue to encroach into the lower end of UNIX territory, while UNIX pushes the envelope of scalability and availability at the very top end. Richard Fichera, the Forrester analyst who carried out the research, predicts an "asymptotic convergence" between the abilities of Linux and those of UNIX.

That means that although UNIX won't necessarily die, the number of workloads for which it makes sense to choose UNIX rather than Linux will trend to zero over time. The pessimist would say that while UNIX may not be dead, sure as eggs is eggs it's dying.

The optimist, on the other hand, would say that there's life in the old dog yet. And that, one suspects, is the point that HP is trying to get across.

Paul Rubens is a journalist based in Marlow on Thames, England. He has been programming, tinkering and generally sitting in front of computer screens since his first encounter with a DEC PDP-11 in 1979.